The Sán Dìu (also known as San Deo, Trai, Trai Dat and Man Quan Coc; Chinese: 山由族; pinyin: Shān yóu zú; Jyutping: saan1 jau4 zuk6; Cantonese Yale: Sanyau Juk; Chữ nôm: 𠊛山由; Vietnamese alphabet: Người Sán Dìu) are a Yao ethnic group in northern Vietnam who speak Yue Chinese (Cantonese), a Sinitic language.
They are believed to have migrated from Guangdong, China around 1600[citation needed].
The group's estimated population as of 2000 was 117,500; the 2019 census put the number at 183,004.
[citation needed] The major religions are Mahayana Buddhism and Taoism, with elements of animism and veneration of the dead.
This ethnic group is mainly concentrated around the Tam Đảo range in Thái Nguyên Province.